Origin & Evolution of Life: September 2011

Applications are currently being accepted for the Origin of Life Gordon Research Seminar (GRS). The Origin of Life GRS is a unique forum for graduate students, post-docs, and other scientists with comparable levels of experience and education to present and exchange new data and cutting edge ideas on origin of life research. The meeting will be held January 7th-8th at Hotel Galvez in Galveston TX, immediately preceding the Origin of Life Gordon Research Conference to be held January 8th - 13th at the same location. Participants in the Origin of Life Gordon Research Seminar are encouraged to participate in the associated Origin of Life Gordon Research Conference.

The Institute for Astronomy (IfA) invites applications for a Postdoctoral Fellowship with interests in the origin of Earth's water to work with the University of Hawai'i's NASA Astrobiology Institute lead team (see http://www.ifa.hawaii.edu/UHNAI/). The UH lead team maintains an innovative and multi-disciplinary research environment linking astronomical, biological, microbiological, chemical, and geological sciences to investigate the origin, history, distribution and role of water as it relates to life in the universe. The program centers around interactions with an interdisciplinary group of postdoctoral fellows. We have a particular need for an individual interested in the origin of Earth's water, and, by analogy, terrestrial planetary volatiles. The work involves geological field work to sample primitive, deep-mantle-plume materials, preparation of samples of melt inclusions in olivines from Hawaiian and Icelandic basalts for isotopic measurements using the petrographic microscope, scanning electron microscope, and electron microprobe, and measurements of D/H ratios and hydrogen abundances in the melt inclusions using the UH Cameca ims 1280 ion microprobe. The Fellowship is for one year and may be renewable up to a total of 3 years assuming satisfactory progress and continued availability of funds. The fellow will receive a stipend of approximately $5,000 per month, a small relocation allowance and basic research costs.

Join us for the next NAI Director's Seminar! Please RSVP if your site will be joining.

Date/Time: Monday, September 26, 2011 11:00AM Pacific

Presenter: David Deamer (University of California, Santa Cruz)

Abstract: Although the physical environment that fostered primitive cellular life is still largely unconstrained, we can be reasonably confident that liquid water was required, together with a source of organic compounds and energy to drive polymerization reactions. There must also have been a process by which the compounds were sufficiently concentrated to undergo physical and chemical interactions. We are exploring self-assembly processes and polymerization reactions of organic compounds in natural hydrothermal environments and related laboratory simulations. We have found that macromolecules such as nucleic acids and proteins are readily encapsulated in membranous boundaries during wet-dry cycles such as those that would occur at the edges of hydrothermal springs in volcanic environments. The resulting structures are referred to as protocells, in that they exhibit certain properties of living cells and are models of the kinds of encapsulated macromolecular systems that would have led toward the first forms of cellular life. We have also determined that RNA-like polymers can be synthesized non-enzymatically from ordered arrays of mononucleotides in lipid microenvironments. We are now extending this approach to template-directed synthesis of DNA and RNA in which lipid-assisted polymerization serves as a model of an early stage of evolution toward an RNA World.

The 2012 Gordon Research Conference on Origin of Life will take place at the Hotel Galvez in Galveston, TX from January 8-13, 2012. This unique interdisciplinary meeting includes chemists, biologists, geologists, astronomers, physicists as well as scientists in related disciplines interested in the origin, and early evolution of Life on Earth and its possible distribution throughout the universe. The 2012 conference will feature recent and cutting-edge results, and sessions will address attempts to fabricate life or life-like systems in the laboratory, the search for extra-solar Earth like planets, recent developments in our understanding of the early history of Earth, Mars, and Titan, prebiotic and organic chemistry on the early Earth and elsewhere in the solar system, and reconstruction of early life forms and genomes, among other exciting topics.

We encourage young scientists, including graduate students and postdoctoral fellows, to attend. Special efforts will be made to promote interactions between invited speakers and junior participants and we expect to be able to provide some financial support to facilitate the latter's participation. Applications for this meeting must be submitted by December 11, 2011. Please apply early, as we expect the meeting to become oversubscribed (full) before this deadline. More information, including afullconferenceprogram,can be found on the conference website: http://www.grc.org/programs.aspx?year=2012&program=originlife.

A case study of last year's Workshop without Walls on "Molecular Paleontology and Resurrection: Rewinding the Tape of Life." appears in the July 2011 issue of PLoS Biology. Authors include Betuel Arslan of the Georgia Tech team, Eric Boyd of the Montana State University team, and members of NAI Central.

Abstract:

The NASA Astrobiology Institute conducted two "Workshops Without Walls" during 2010 that enabled global scientific exchange--with no travel required. The second of these was on the topic "Molecular Paleontology and Resurrection: Rewinding the Tape of Life." Scientists from diverse disciplines and locations around the world were joined through an integrated suite of collaborative technologies to exchange information on the latest developments in this area of origin of life research. Through social media outlets and popular science blogs, participation in the workshop was broadened to include educators, science writers, and members of the general public. In total, over 560 people from 31 US states and 30 other nations were registered. Among the scientific disciplines represented were geochemistry, biochemistry, molecular biology and evolution, and microbial ecology. We present this workshop as a case study in how interdisciplinary collaborative research may be fostered, with substantial public engagement, without sustaining the deleterious environmental and economic impacts of travel.

In recent years, scientists have found evidence that a 'near complete' biological nitrogen cycle existed in the oceans during the late Archean to early Proterozoic (from 2.5 to 2 billion years ago). Modern bacteria use an enzyme called nitrogenase to cycle nitrogen from one form to another. This enzyme is dependent on the presence of metallic elements like iron (Fe), vanadium (V) and, most often, molybdenum (Mo). However, ancient oceans didn't contain much molybdenum. Could Fe-nitrogenase or V-nitrogenase have played a larger role in the archaean oceans than they do today?

To answer this question, a team of researchers at NAI's Montana State University and Arizona State University teams studied the phylogenetic relationships between the proteins that allow nitrogenase to interact with each of the three elements. Their results suggest that the protein (known as Nif protein) actually developed in methanogenic microorganisms, and was then incorporated into bacteria by lateral gene transfer around 1.5-2.2 billion years ago.

Ultimately, if Mo-nitrogenase originated under anoxic conditions in the Archaean, it would have likely happened in an environment where both methanogens and bacteria coexisted, and where molybdenum was present for at least part of the time.

The emergence of enzymes like Mo-nitrogenase was a significant step in the evolution of life, and had powerful repercussions for planet Earth and its biosphere as a whole. This research can help answer important questions about the environmental conditions that were present on the early Earth, and the interactions that occurred between life and the ancient planet.

The results were published in the May edition of the journal Geobiology

Some asteroids may have been like "molecular factories" cranking out life's ingredients and shipping them to Earth via meteorite impacts. Now it appears that at least one asteroid may have been less like a rigid assembly line and more like a flexible diner that doesn't mind making changes to the menu.

Astrobiologists at NAI's Goddard Space Flight Center and Carnegie Institution of Washington teams studying the carbon-rich Tagish Lake meteorite have discovered that different pieces of it have greatly differing amounts of amino acids, the building blocks of proteins and essential ingredients to life as we know it.

In January, 2000, a large meteoroid exploded in the atmosphere over northern British Columbia, Canada, and rained fragments across the frozen surface of Tagish Lake. Because many people witnessed the fireball, pieces were collected within days and kept preserved in their frozen state. This ensured that there was very little contamination from terrestrial life.

"The Tagish Lake meteorite fell on a frozen lake in the middle of winter and was collected in a way to make it the best preserved meteorite in the world," said Dr. Christopher Herd of the University of Alberta, Edmonton, Canada, lead author of a paper about the analysis of the meteorite fragments published June 10 in the journal Science.

"The first Tagish Lake samples -- the ones we used in our study that were collected within days of the fall -- are the closest we have to an asteroid sample return mission in terms of cleanliness," adds Dr. Michael Callahan of NASA's Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper.